The classic circulation water pumps used in heating systems are just the best for #aquaponics. We have an #upcycled #pump that worked in our house for 20 years. It stopped this morning. I was carrying watering cans from the filter to the plants (aquaponic equivalent of cpr) until we got a replacement, a virtually identical one, the tech haven't changed. We thought the OG pump is dead, we disassembled it and it turned out it was just limescale! There's nothing to break there, this pump can work another 20 years. We removed the scale, added some vaseline and reassembled the pump. It works again like nothing ever happened! It's amazing.